If you turn on gfx-rendered widgets in apprunner (add
user_pref("nglayout.widget.mode", 2); to your prefs), you will see that the
content window never loads, with the message "Scheduling later attempt to set
content window" If you trace it down, you'll find that someone is loading
about:blank.
Similarly, I want to initialize an empty text field with about:blank instead
of using a dummy empty file as I do now, but I get the same sort of hang. You
can try this yourself by changing nsGfxTextControlFrame.cpp:
- #define EMPTY_DOCUMENT "resource:/res/html/empty_doc.html"
+ #define EMPTY_DOCUMENT "about:blank"

Changing all Networking Library/Browser bugs to Networking-Core component for
Browser.
Occasionally, Bugzilla will burp and cause Verified bugs to reopen when I do
this in a bulk change. If this happens, I will fix. ;-)